Antibacterial and Antibiofilm Activity of Titanium Treated with Hybrid Phospholipid Films Containing Carbonate Hydroxyapatite and Silver Nanoparticles

Bacterial contamination and low osteogenic activity are the major causes of dental implant failure. The development of titanium coatings has provided new research directions to improve both antibacterial and osteogenic activity. In this study, we constructed phospholipidic films containing carbonate hydroxyapatite added or not to silver nanoparticles. The purpose was to reduce the biofilm formation while maintaining the osteogenic potential of surfaces. Phospholipid monolayers were transferred to titanium by Langmuir-Blodgett (LB) technique and resulted in dense, ordered and uniform films. Modified surfaces were evaluated by X-ray photoelectron spectroscopy, energy-dispersive spectroscopy, Fourier-transform infrared spectroscopy, and atomic force microscopy to confirm that films were successfully coated onto the titanium substrate. In addition, surface free energy and roughness analyses indicated that surfaces were smooth and hydrophilic. ICP-OES analysis confirmed the absence of silver nanoparticle lixiviation from the coatings. Furthermore, the coatings had great biocompatibility and promoted the proliferation of osteoblast-like cells. Microbiological findings showed that biofilm formation and bacterial adhesion were significantly reduced for the experimental coatings; species closely related to peri-implant diseases and associated with increased biofilm volume were shown reduced. Addition of silver nanoparticles did not improve biofilm control. In conclusion, the phospholipidic films proposed to modify the titanium surfaces are beneficial for osseointegration and can act as a promising method to reduce the biofilm formation and bacterial colonization for dental implants.